Figure 4.

Modulation of AtTPI enzymatic activity by redox agents. AtTPIs enzymatic activities after treatment for 2 h at 37°C with diverse redox agents in comparison to the enzymatic activity of untreated proteins. (A) Incubation of cTPI and pdTPI in the presence of 1 mM diamide (DA) (black bars). The reversibility of the reaction was tested by incubating with 20 mM DTT (white bars). (B) Incubation of cTPI and pdTPI in the presence of 0.2 mM H₂O₂ (black bars). The reversibility of the reaction was tested by incubating with 20 mM DTT (white bars). (C) Incubation of cTPI and pdTPI in the presence of 2.5 mM GSSG (black bars). The reversibility of the reaction was tested by incubating with 2.5 mM GSH(white bars) or 20 mM DTT (white bars with black lines).